There are several known solutions to turn off full or partial functionality of an integrated circuit (IC). One of these known solutions involves a software approach, where, for example, a computer program disables an IC until a special data sequence is input into the IC via the computer program. Another known solution to turn off an IC involves a hardware approach, where, for instance, electronic fuses are embedded in the IC and are blown to disable the IC. A third known solution is to embed an electronically-erasable random-access memory (RAM) in an IC.
However, each of these known solutions has shortcomings in that they can be tampered with or permanently disable an IC. For example, a chip that uses the software approach may be rendered ineffective if a computer program is discovered, hacked into, and altered, or if encrypted communication between the computer program and the chip is intercepted, deciphered, and altered. An IC that utilizes the hardware approach is permanently disabled after, for example, an electronic fuse is blown to disable the IC, rendering the IC useless. Using multiple electronic fuses may allow the IC to be disabled more times, but this method is also area-intensive with respect to the IC and still does not avoid permanent disablement of the IC in the long-term. In another hardware-oriented example, using registers may be insecure if they are discovered and saved states in the registers are altered. Lastly, an electronically-erasable RAM may be affected by a high-radiation environment and alpha particles, for instance.
Accordingly, there exists a need in the art to overcome the deficiencies and limitations described hereinabove.